Various techniques have long been used for the extrusion of different types of materials. For example, in the manufacture of fine metal wires having diameters ranging between a few thousandths and a few tenths of a millimeter from wires having diameters of one or more millimeters, the raw material is passed through a set of dies of successively decreasing diameters until the desired wire diameter is obtained. In the case of copper drawing, for example, a machine designed to produce a wire having a diameter of 0.02 mm from a starting wire having a diameter of 0.1 mm, comprises at least twenty dies. Apart from the high cost of producing machines of this type, it must be appreciated that the preliminary manual operations for successively inserting the specially tapered end of the wire into each die in the series until sufficient lengths for winding on the winches are obtained, are extremely long and tedious. In addition, the diameters of the successive dies must be very exact: for example, the permissible tolerance in the case of a wire having a diameter of 0.01 - 0.02 mm is 0.001 mm. Furthermore, friction affecting the metal inside each die frequently causes breaks in the wire upstream of the die which result in loss of time and material.